Monday, 31 December 2012

Assume that you want
to deploy 50 OvDCs or you want to disconnect CD-ROM for 200 VMs. Are you going to do this manually ??? Here is
the power of automation tools where vCO is one of them.

vCO automation is based on workflows. Each workflow is a flowchart which defines how vCO will operate to achieve the desired result.

vCO by default has
predefined workflows on installation. However, thoseare providing basic functions and won't be
sufficient for your custom requirements.

In case vCO Server failed during workflow execution, two options are available:

a. Resume workflow run once the server is back

b. Don't resume workflow run (set as FAILED)

vCO Web View

You can run
workflows manually or schedule them to run automatically. Adding to this vCO
has capability to create policies for access and authorization to workflows.

Manual
execution of vCO workflows can be done using vCO client. Adding to thisvCO server has built-in web view component.
This is used to provide front-end web access to orchestrator
workflows (without any vCO client installable or java version). vCO web view
component has one pre-built front-end page called
weboperator.

Advantage of web view: You don't need to create users to access vCO client and define privileges to execute workflows without edit capability. With web view, users can only execute workflows.

To start with
creating workflows, in vCO client you need to select Design from drop-down list. The first tab in inventory is workflow
tab. There you can see the default workflows located inside folders. You can
create your custom workflows in those folders or preferably, create your own
folders (Right-Click > Add Folder).

Right-click
on your custom folder and select New Workflow.

In General tab,

1. Supply the name of your
workflow as well as description

2. For any major change in the
workflow, you canincrease the
version number. This is important to be able to revert back to the
desired version when required. To revert back, you need to select Show Version
History
hyperlink. This will list all previous versions where you want to select
the one to revert.

The
core element in your workflow is Schema section.
This is the place where the actual programming of your workflow takes place to
achieve the desired functionality.

There are many
programming elements provided by vCO which can be placed in Schema. All vCO elements are following
drag-drop model where you drag them from inventory and drop them in schema. You
need to drop the elements between Start & Stop .

Here
is the list of common elements:

- Workflow
Element

This allows the
usage of predefined workflows (either pre-installed with vCO server or custom
created) in your custom workflow. Multiple workflow elements can be placed in
your custom one.

Once dropped in
Schema, new window will open to select the desired function of your workflow
element.For example, searching with
'Org' keyword, will list all workflows having this keyword (add an organization, upgrade an org vDC capacity, etc).

Each Workflow
Element is made of a combination of other Workflows, Action Elements, Sleep Elements,
Scriptable Tasks, etc.

- Action Element

Instead of executing
full workflow element, you may be looking for specific one-step action such as listing
hard disks in VM or listing VMs in a vAPP. For this purpose, you can use Action
Element instead of Workflow Element.

In fact Action
Element is running a predefined script in the background to do the desired
function. If you try to edit the action element and verify the Scripting tab, you will find out the script used.
E.g. GetVdcOrg action element in below
snapshot is running the script

Sometimes you may
need to use actions which aren't available in vCO. For this purpose, you may
use Scriptable Task and write your own
java script to perform the desired function.

Note: Another option is to create your own custom Action Elements.

- Sleep Element

This is used to
introduce delays between elements which is required sometimes due to the
processing time. We will see this element later when we give detailed example.

- Decision Element

This is acting as IF statement in C/Visual Basic programming
where you have two conditions and you want different actions for each one.

In fact before creating schema, there is an important element needs to be present. We said that schema defines the algorithm of your workflow. But what are the elements which will be processed by schema ??

Those are called variables which should be ready before creating schema. There are three types of variables used in vCO:

- Input
Variables(IN Tab) (those should be entered
manually by users when workflow is executed)

- Output
Variables (OUT Tab)
(those are variables passed to the next element in the workflow. It
possible as well to pass them between workflows)- Attributes
(General Tab)
(those can be input or output variables however they are pre-set and won't
require manual intervention. Those are local to the workflow)

Each type of the
above variables can be classified as string, number, Boolean, vcloud:vapp,
VC:VM, vcloud:VM, etc. Also, each of these types can be single unit or array.

Variables are bonded to vCO
elements in Schema using Visual Binding section.

Finally, I would
like to touch on how to present input variables to users when executing
workflows. This can customized from Presentation
section of your workflow.

From this section
you can set the display order of the input variables and display name of each
variable. One option I liked is 'Properties'.
This enables you to set the properties of input variable such as mandatory,
hide input, show input, max value, minimum value, default value, etc. Although
this is optional but it very important. For example what will happen if the
user executed the workflow and left the input variables 'null'. This will lead
to unexpected and undesirable output which can be avoided by setting mandatory
option in the properties (the workflow won't execute without entering this
variable).

Also, you can group
input variables based on your classifications. You will see this classification
during workflow execution. You can do this using Right-Click on Display Group
and Select New Step.